The present invention relates to a blower module for use with a commercial air-purifying system. More particularly, it relates to a blower module incorporating an exhaust chute for directing airflow to an associated exhaust port during operation.
In recent years, there has been a growing interest to improve environmental air conditions in homes and in commercial settings, such as offices, restaurants, taverns, bowling alleys, hospitals, laboratories, lavatories, and the like. As more information has been made available to the public concerning the hazards of indoor air pollution, there has been an increased demand for filtering devices that can be used to effectively improve air quality.
A self-contained, stand-alone air cleaning or filtration unit is normally employed to clean air in both residential and commercial settings. Stand-alone air filtration units can assume a wide variety of forms, but generally include a housing maintaining one or more applicable filter materials and a fan or blower unit. The housing defines an inlet, at which the filter(s) is disposed, as well as an outlet or exhaust port. Most commercial applications include a false ceiling, such that the housing is readily "hidden" above the ceiling, with only the inlet (or an associated grille) being visible to persons within the room. During use, the fan or blower unit is operated to draw room air through the filter via the inlet. The filter material or media removes undesirable air-borne particles and/or gaseous contaminants or odors, such as dust, smoke, pollen, molds, tobacco odor, volatile organic compounds (VOCs), etc., from the airflow. Following interaction with the filter material, the now "cleansed" air is forced, via the blower, back into the room through the outlet port. A continuous intake and supply of air preferably generates a desired air re-circulation pattern within the room.
An alternative concept to the stand-alone filtration unit is a modular air-purification system. With this configuration, a blower module, one or more filter modules and one or more supply modules are separately provided and installed over a room of interest. The blower module includes a blower unit and is fluidly connected to the filter module(s) and the supply module(s) by standard ductwork. Perhaps due to the industry acceptance of self-contained air-filtration units, as well as the engineering obstacles present by a modular configuration, only one modular-type air cleaning system has been identified, advertised as being available under the trade name Crystal-Aire.RTM. from United Air Specialties, Inc. of Cincinnati, Ohio. According to a trade brochure, this air cleaning system apparently includes separate blower and filter units designed to be connectable by a single duct. This configuration allows the blower unit to be installed apart from the filter unit. However, the blower unit has only one inlet port and one outlet port, such that the system is restricted to a single filter unit connected to the inlet port, and a single supply (or forced air return) unit connected to the outlet port. In theory, it may be possible to cormect two or more filter units and/or supply units in series to the blower unit. Unfortunately, overall blower efficiency may be greatly reduced.
An additional concern associated with a modular air-purification system apparently not addressed by the described Crystal-Air.RTM. product is a need to exhaust air from the blower module apart from air directed through the supply module. When installed over a room of interest, room air is drawn through the filter module, cleansed, and then returned to the room via the supply module. For many applications, it is desirable to maintain a negative pressure differential within the room for more efficient air circulation. This concept is apparently not addressed by the Crystal-Aire.RTM. system. However, in accordance with designs of other available commercial air handling units, an exhaust port separate from the outlet port associated with the supply module could be formed in the blower module housing, with a portion of the filtered air being exhausted through the exhaust port to an area outside the room of interest. To ensure airflow through the exhaust port, the accepted design technique is to form a relatively large exhaust plenum within the unit's housing (in addition to an inlet plenum for drawing air into the housing). The large volume of the exhaust plenum is required to establish a static pressure within the plenum, so that an acceptable volume of air will exit from the housing through both the outlet port and the exhaust port.
Air-purifying system are extremely popular and beneficial. While stand-alone, self-contained air filtration units are widely accepted, modular air-purifying systems appear highly viable. However, certain potential drawbacks, such as efficient, low-cost exhaust requirements remain unresolved. Therefore, a need exists for a blower module for use with an air-purifying system incorporating a low-cost, reduced-sized exhaust configuration.